How to Install the Curt Triflex Brake Controller in a 2019 Toyota Highlander

Updated 11/09/2025 | Published 01/14/2025

Products Featured in This Question

Hopkins Endurance Multi-Tow 4-Way Flat to 7-Way RV Trailer Adapter w/ 4-Way Vehicle End Plug

(65)

$41.71

12 Gauge 2 Conductor Jacketed (Brake) Wire Per Foot

(508)

$3.16

Ring Terminal - 12-10 Gauge Wire - 3/16" Ring ID

(69)

$1.45

Curt TriFlex NEXT Trailer Brake Controller - 1 to 4 Axles - Proportional

(926)

$135.95

Universal Wiring Adapter for Curt Trailer Brake Controllers

(457)

$11.01

Hook Probe Circuit Tester

(60)

$13.03

Question:

Good morning. I recently had a hitch and 7 way wiring harness installed on my pre-owned 2019 Toyota Highlander by Uhaul. They installed the CQT118449 with the 7-way addition part number: 47185 for my camper. Ill be picking up a Curt Triflex brake controller 51140 I think in the coming days, but I am having a hard time finding information on its installation. Videos have mentioned needing quick connects, but details are non-existent. My questions are: How would I go about installing a Triflex if a 7-way wiring has already been installed and if I need additional wiring for my SUV. As far as I can tell, every 2019 Highlander v6 has a standard tow package. Any help, guidance, or links to products would be greatly appreciated. The U-haul crew were unfortunately inexperienced.

asked by: Greg D

Helpful Expert Reply:

Hey Greg! We hear that quite often about U-Haul. The Hopkins 47185 is almost identical to our item # HM47180, so if they installed it correctly you should have a blue wire ran into your 2019 Toyota Highlander's cab. If not you'll need to use item # 12-2-1 because it's what sends the signal from the brake controller to your 7-way connector. If they just dead-ended the wire at the 7-way, I would go back and complain personally.

There is no brake controller adapter in the 2019 Toyota Highlander, so you will need to manually wire the Curt TriFlex NEXT Trailer Brake Controller item # C24VV using the Universal Wiring Adapter for Curt Trailer Brake Controllers item # C51515.

You'll need to connect the blue wire to the brake controller wire, I mentioned earlier. The white wire to the ground, or just make one yourself by attaching it to bare metal using item # 44-5310A. The black wire to a power source you can locate using a Circuit Tester like item # PTW2993. The red wire goes to the stop light switch circuit, which is a little more difficult to find. It can be found by testing the bundle of wires attached to the brake pedal. The one you're looking for should only have power while the pedal is depressed. We don't have access to wire color info.

expert reply by: Jerred H

Jerred H.

11/3/2025

Hey Greg, how did things go wiring the Curt Triflex brake controller in your Highlander? Were you able to locate the correct stop light switch wire and get everything connected? Your update could make it easier for others adding a controller to a similar setup.

Greg D.

11/8/2025

@JerredH Ended up going to a local shop after. Saying the U-Haul crew was inexperienced was an understatement. My car actually had to get towed out of their garage, they messed up so badly. Sadly I don't have much help to offer anyone (except a warning to stay away from U-Haul) as I ended up going to a local shop and they hooked everything up for me.

Jerred H.

11/9/2025

@GregD Happy to hear you found a local shop that was able to get you set up. We hear quite a few horror stories about U-Haul messing up and recommending the wrong parts but I gotta say I have never heard of someone having to get their vehicle towed away from one of their locations.